PLACENTIA — The Southern California teacher whose students found her hanging from her classroom ceiling knew the devastating effects of suicide: Her own father went missing and was found dead with a bullet wound to his head after committing suicide nearly four years earlier.

Jillian Jacobson, 31, had spoken with students about her father’s suicide and had counseled one class of students just a few weeks ago, saying if they ever felt down, they should ask for help.

Jacobson did a weeklong unit on depression for freshmen, emphasizing that suicide wasn’t the answer to anyone’s problems and it affected many people greatly.

On Monday, students arriving to their morning photography class found the door to Jacobson’s room locked. Thinking their teacher was late, the students asked another teacher to unlock the door. When they opened it, they found Jacobson hanging from the ceiling.

Two school staff members got her down while another worker called 911.

“We have a teacher that’s down,” the caller said in a hurried voice.

“Do you know if they’re breathing?” the 911 dispatcher said.

“All I know is another teacher called crying and security is just saying, ‘Get them down here fast,'” said the caller, identified only as Melanie.

Paramedics arrived to find Jacobson in full cardiac arrest, and they were unable to resuscitate her. Police are calling Jacobson’s death a suicide, though no note was found and detectives are not releasing any information on what may have troubled the popular teacher.

Jacobson’s stunning death stood in stark contrast to the teacher students said they knew. They described her as someone cheerful and trusted who inspired in many a love of photography. She lived in nearby Anaheim in a quaint, gray home with a white picket fence.

Yet Jacobson had also experienced significant hardship in recent years. In 2011, her father went missing after leaving his job. Richard Prisbrey, 55, was found two days later, near his car in an isolated desert area more than an hour away. A coroner’s report ruled his death a suicide.

It was an event that students said clearly troubled Jacobson, but she kept her composure and didn’t get emotional when she talked about it with her class. No one could point to any recent warning signs that she was distressed, though one student noted that she lost a lot of weight.

After Monday’s stunning discovery, shock emanated throughout the school.

Alexandra Sanchez, 18, recalled how her teacher left the room and then came back, flustered, and told the class, “Mrs. Jacobson just hung herself.” The classroom went numb.

“It was silent,” she said. “A shock and silence.”

Later, students were escorted into the gym and a police officer told them Jacobson had committed suicide, but that there was no other information.

Monday evening, 500 students gathered outside the school’s gate, lighting candles and leaving written tributes for their teacher. On Tuesday, the candles remained at the site, a few still burning.

Assistant Superintendent Candy Plahy said the students who saw the hanging scene are being closely monitored and provided special counseling.

“These are kids who were particularly close to this teacher,” Plahy said. “Coming in and finding your teacher is no longer alive is traumatic. They need support.”

In their first-period class Tuesday, a school administrator delivered an announcement on the loudspeaker, saying they would all miss Jacobson and had to stay united.

Several students said they were confused and didn’t know how to process the information. Others couldn’t stop replaying the events in their heads. Later, in classes, teachers told students it was OK to feel mad or upset and encouraged them to talk with counselors.

Some students asked questions. Others remained silent.

“Everybody was sad,” Sanchez said.

Jillian Jacobson’s classroom door was locked, a picture of the smiling brunette placed out front along with notes and flowers.

Plahy said the classroom is expected to remain closed for the rest of the year.

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